Origin of the water vapor responsible for the European extreme rainfalls of August 2002: 2. A new methodology to evaluate evaporative moisture sources, applied to the August 1113 central European rainfall episode
New method has mapped the evaporation attributed to C-European extreme rainfalls Sequence of evaporation shows increased contribution from continental areas Preceding methods could have overestimated attribution to remote oceanic regions An innovative technique has been developed to assess moisture...
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Published in | Journal of geophysical research. Atmospheres Vol. 116; no. 21 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Washington
Blackwell Publishing Ltd
01.11.2011
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Subjects | |
Online Access | Get full text |
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Summary: | New method has mapped the evaporation attributed to C-European extreme rainfalls Sequence of evaporation shows increased contribution from continental areas Preceding methods could have overestimated attribution to remote oceanic regions An innovative technique has been developed to assess moisture sources contributing to precipitation. It represents an advance with respect to previously developed methodologies because it allows to discriminate more effectively between terrestrial versus oceanic sources, and also to detect with greater precision the relative importance of remote versus local sources together with the sequence of evaporation associated with a rainfall event. It is based upon the use of a mesoscale model to simulate a selected precipitation episode and a Lagrangian trajectory model to evaluate three-dimensional back-trajectories in order to track the vapor parcels transporting the target precipitation to their surface evaporative sources. An extreme sequence of rainfall events occurred over central Europe between August 11th and 13th is chosen to put the methodology into test. A domain centered in the region and spanning 6372 km in the WE direction and 5940 km in the NS direction is chosen to assess moisture sources. Results show the evolving role of various sources throughout the duration of the event, indicating that they shift from the southern to northern and eastern source regions, while a simultaneous decrease of marine sources with respect to terrestrial sources occurs from the onset of the event to its ending phase. The capability of discriminating moisture sources with precision is an important requirement to better understand the mechanisms of extreme rainfalls. |
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ISSN: | 2169-897X 2169-8996 |
DOI: | 10.1029/2010JD015538 |